JPH04246627A - Camera using film provided with magnetic storage part - Google Patents

Abstract

PURPOSE:To properly write information in accordance with each information quantity without using a high-accuracy encoder mans which is expensive. CONSTITUTION:The above camera is provided with an information quantity detection means 103b for detecting the information quantity to be written in each photographic frame by a magnetic head 6 and a control means 103 for controlling the timing of write based on the output of the encoder means 108 which detects the feeding quantity of a film in accordance with the detected result by the means 103b.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention provides a film with a magnetic memory section, which is equipped with a magnetic head for writing information into a magnetic memory section provided on the film, and an encoder means for detecting the amount of film feeding. This relates to improving the camera used.

0002

2. Description of the Related Art In recent years, a camera has been disclosed, such as in US Pat. No. 4,864,332, which is equipped with a magnetic head and uses the magnetic head to write information into a magnetic storage section provided on a film.

Furthermore, in such cameras, the film is fed at a constant speed in order to record information at an appropriate density within a predetermined range of one frame.

0004

[Problem to be Solved by the Invention] However, in the conventional example described above, the length of one frame of film is short, and constant speed feeding is not originally required, so accurate constant speed feeding is impossible. It was close to Therefore, it was essential to provide an encoder means. However, when magnetic recording is performed by detecting the amount of film feed using an encoder means, the amount of information to be recorded varies from frame to frame, so conventionally the recording density must be set to the maximum amount of information. Of course, even when the amount of information is small, writing at a high frequency is required, which not only requires high precision of the encoder means but also increases the cost of the encoder means.

[0005] In view of the above points, an object of the present invention is to make it possible to write appropriate information according to each amount of information without using a highly accurate encoder means.

[0006]

[Means for Solving the Problems] The present invention provides an information amount detection means for detecting the amount of information to be written in each photographic frame by a magnetic head, and a method for detecting an amount of information according to the detection result of the information amount detection means.
A control means for controlling the write timing based on the output of the encoder means is provided.

[0007]

[Operation] The information amount detection means is for detecting the amount of information to be written in each photographic frame by the magnetic head,
The control means controls the writing timing based on the detection result of the information amount detection means, that is, the amount of information to be written, and the output of the encoder means for detecting the amount of film feeding.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 2 is a view showing a camera according to an embodiment of the present invention using a film having film positioning perforations and a magnetic storage section, with the back cover removed.

In FIG. 2, 1 is a camera body, 2 is a finder, 3 is a film cartridge chamber, 4 is a fork for rewinding the film into the cartridge, and 5 is a film aperture.
6 is a magnetic head, 7 is a film take-up spool,
Reference numeral 8 denotes a roller for detecting the amount of movement of the film, which is provided with one film positioning perforation per frame and a magnetic storage section. It is designed to be pressed into contact.

FIG. 1 is a circuit block diagram showing a schematic configuration of the camera shown in FIG. 2. As shown in FIG.

In FIG. 1, 101 is a photometering circuit that measures the brightness of the subject to be photographed, 102 is a distance measuring circuit that measures the distance to the subject necessary for adjusting the focus of the photographic lens, and 103 is an internal circuit. RA stores various information in
A control circuit includes an M103a and a determination unit 103b that determines the amount of information to be written in each frame, and controls various circuits of the camera; 104 is the first release button of the camera (not shown);
A switch that is turned on by a stroke (hereinafter referred to as SW1)
, 105 is O at the second stroke of the release button.
A switch 106 turns on and off in conjunction with opening and closing of the back cover (hereinafter referred to as SW2), a switch 107 detects the presence or absence of a film cartridge (not shown).

Reference numeral 109 denotes a motor control circuit for controlling a film feeding motor (not shown), which winds up the film by rotating in the forward direction and rewinds the film by rotating in the reverse direction. 110 is a shutter control circuit that controls exposure to the film, 111 is a lens control circuit that controls the lens barrel so that the subject is in focus, and 112 is a magnetic storage section of the film using the magnetic head 6 shown in FIG. A head control circuit that writes information to and reads information from the head, 108 is a roller.
ON and O in conjunction with the pulse plate that rotates with the drive of 8.
This is an encoder that generates a pulse train in accordance with the state of the FF switch 8b, that is, the amount of film feeding.

The operation of the camera with the above configuration will be explained using the flowcharts of FIGS. 3 and 4. "Step 1" It is determined whether or not the back cover is closed based on the state of the back cover switch 106. If the back cover is closed, the process goes to step 2, and if it is not closed, step 1 is repeated. "Step 2" It is determined from the state of the switch 107 whether or not there is a film cartridge in the film cartridge chamber 3. If there is, the process goes to step 3, and if there is not, the process returns to step 1. "Step 3" The film feeding motor is rotated in the normal direction via the motor control circuit 109 to start winding the film. "Step 4" ON, O as the roller 8 rotates
A signal to be FF, that is, a pulse signal, is input from the encoder 108. ``Step 5'' Is there a cut in the pulse train of the encoder 108 output?
It is determined whether or not the pulse signal has fallen and no pulse signal is generated, and one frame has been fed. If there is a break in the pulse train, the process goes to step 6; if there is no break, the process returns to step 4. "Step 6" Detect the number of frames on the film by counting the breaks in the pulse train. “Step 7” Shoot 1 frame from the information in step 6.
It is determined whether it is the second one or not, and if not, step 4
However, if it is the first frame to be photographed, the process advances to step 8. "Step 8" Normal rotation of the film feeding motor is stopped via the motor control circuit 109. "Step 9" Check the state of the switch SW1, which is turned ON by the first stroke of the release button of the camera (not shown). If it is OFF, the process stays at step 9, and if it is ON, the process goes to step 10. "Step 10" The photometric circuit 101 is operated to measure the subject brightness. "Step 11" The distance measuring circuit 102 is operated to measure the distance to the subject. "Step 12" Check the state of switch SW2, which is turned on by the second stroke of the release button (not shown), and turn it on.
If so, proceed to step 14 in FIG. 4; if OFF, proceed to step 13. "Step 13" Check the status of switch SW1 again,
If it is ON, go to step 12; if it is OFF, go back to step 9. "Step 14" Focus adjustment is performed by the lens control circuit 111 based on the distance measurement result in step 11. "Step 15" Based on the photometry result in step 10, the shutter control circuit 110 exposes the film. "Step 16" The film feeding motor is rotated normally via the motor control circuit 109 to start feeding the film to the next frame. "Step 17" Here, the amount of information to be recorded in the shot frame, such as shutter speed, aperture value, shooting date and time, exposure compensation value, comment, etc., is checked, and the number of bits of information is "
It is determined whether or not the value is smaller than "N1". As a result, if "amount of information<N1", the process proceeds to step 23; otherwise, the process proceeds to step 18. "Step 18" It is determined whether the number of bits of information is smaller than "N2". As a result, if "information amount<N2", the process proceeds to step 22; otherwise, the process proceeds to step 19. "Step 19" It is determined whether the number of bits of information is smaller than "N3". As a result, if "information amount<N3", the process proceeds to step 21; otherwise, the process proceeds to step 20. "Step 20" A subroutine of "Method 4" to be described later is executed. "Step 21" A subroutine of "Method 3" described later is executed. "Step 22" A subroutine of "Method 2" described later is executed. "Step 23" A subroutine of "Method 1" described later is executed. "Step 24" Continue to input the output of the encoder 108. "Step 25" Determine whether there is a break in the pulse train. If there is no break, return to step 24; if there is, go to step 2.
Proceed to step 6. "Step 26" Assuming that one frame has been fed, the mode
Normal rotation of the film feed motor is stopped via the motor control circuit 109. "Step 27" Determine whether the film has finished,
If the process has not been completed, the process proceeds to step 9 in FIG. 3, and if it has been completed, the process proceeds to step 28. "Step 28" The film feed motor is reversed via the motor control circuit 109 to begin rewinding the film into the film cartridge. "Step 29" The output of the encoder 108 is input, and it is determined whether or not rewinding of the film has been completed. As a result, if the process has not been completed, the process remains in step 29, and upon completion, the process proceeds to step 30. "Step 30" The reverse rotation of the film feed motor is stopped via the motor control circuit 109. Then step 1
Return to.

With the above steps, the series of operations is completed.

FIGS. 5(a) to 5(e) illustrate the output of the encoder 108 described above and the write timing signals in "methods 1 to 4" performed in steps 23 to 20.

FIG. 5(a) shows the output waveform of the encoder 108.

FIG. 5(b) shows that the encoder is encoded during one frame.
Less than one-third of the number of pulses output from the da 108,
In other words, it is less than "N1", the interval between falling edges is equal, and the recording method of "Method 1" indicates 1 bit "0" or "1" depending on whether the position of the rising edge is towards the front or the back. Writing as the film moves is performed in complete synchronization with the output of the encoder 108.

FIG. 5(c) shows the write timing signal in "Method 2", in which the falling edge is completely controlled by the output of the encoder 108, but the "0"
The position of the rising edge indicating "1" or "1" is controlled to be located before or after the rising edge of the encoder 108.

FIG. 5(d) shows a write timing signal in "Method 3", in which the falling edge of the write data is synchronized with the falling and rising edges of the encoder 108. , and whether it is closer to the front or the back between the falling edges of the write data (“0” or “1”).
) from one pulse period of the previous encoder 108,
Control rising edges.

FIG. 5(e) shows the write timing signal in "Method 4" when the amount of information to be written is the largest. control.

FIG. 6 shows that in step 23, FIG.
12 is a flowchart showing the operation at the time of writing according to "Method 1" performed as in (b). "Step 501" A pulse signal from the encoder 108 is input. "Step 502" The falling and rising edges of the pulse signal from the encoder 108 are detected, and by performing this edge detection, the process proceeds to step 503. "Step 503" Edges are counted and assigned to memory n. "Step 504" Find the remainder when dividing the value of memory n by "3", and if it is "0", proceed to step 505, and "
0'', the process advances to step 508. "Step 505" The data to be written is sequentially read one bit at a time. "Step 506" Set the write level to "L". "Step 507" It is determined whether there is write data or not, and if there is no write data, this subroutine is ended and
Proceed to step 24 in FIG. 4, and if there is, return to step 501.

If the remainder is not "0" in step 504, the process proceeds to step 508 as described above. "Step 508" Determine whether the remainder is "1" or not,
If it is "1", the process proceeds to step 509; otherwise, if the remainder is "2", the process proceeds to step 511. “Step 509” The data entered in step 505
It is determined whether or not the data is "1", and if it is "1", the process advances to step 510; otherwise, the process returns to step 501. "Step 510" Set the write level to "H".

If the remainder is not "1" in step 508, the process proceeds to step 511 as described above. "Step 511" It doesn't matter if it is a remainder of "3", but
This step becomes necessary when advancing the data from 1/3 to 1/4. In this case, the process proceeds from step 511 to step 512. “Step 512” The data entered in step 505
It is determined whether the data is "0" or not, and if it is "0", the process proceeds to step 513; otherwise, the process returns to step 501. "Step 513" Set the write level to "H".

From the above, the waveform shown in FIG. 5(b) is obtained.

FIG. 7 shows that in step 22, FIG.
12 is a flowchart showing the operation at the time of writing according to "Method 2" performed as in (c). "Step 601" A pulse signal from the encoder 108 is input. "Step 602" The falling and rising edges of the pulse signal from the encoder 108 are detected, and the process proceeds to step 603 by performing this edge detection. "Step 603" Edges are counted and assigned to memory n, and at the same time, the time Δtn from the previously detected edge to the current edge is stored. "Step 604" Find the remainder when the value of memory n is divided by "2", and if it is "0", proceed to step 605; otherwise, proceed to step 612. "Step 605" Write data is input in bits. "Step 606" Set the write level to "L". "Step 607" Take the average of the past three Δt,
Furthermore, the time reduced to "1/2" is substituted into the memory T. Note that the reason for taking the average of the past three times is to reduce the influence of variations in Δt. “Step 608” The data entered in step 605
It is determined whether the data is "1" or not, and if it is "1", the process proceeds to step 609; otherwise, the process proceeds to step 611. "Step 609" It is determined whether or not time T has elapsed since the edge detected this time, and when time T has elapsed, the process proceeds to step 610. "Step 610" Set the write level to "H". "Step 611" It is determined whether or not the data to be written has been completed. If it has not been completed, the process returns to step 601, and if it has been completed, the process advances to step 24 in FIG.

In step 604, the value of memory n is set to "2".
If the remainder after dividing by `` is not ``0'', the process proceeds to step 612 as described above. "Step 612" Take the average of the past three Δt,
Furthermore, the time divided by 1/2 is substituted into the memory T. "Step 613" Determine whether the data is "0". If it is "0", proceed to step 614; otherwise, proceed to step 611. "Step 614" Detects whether time T has elapsed since the edge detected this time, and if it has elapsed, step 6
Proceed to step 15. “Step 615” Set the write level to “H” and proceed to step 611.

From the above, the waveform shown in FIG. 5(c) is obtained.

FIG. 8 shows that in step 21, FIG.
12 is a flowchart showing the write operation according to "Method 3" as shown in FIG. 3(d). "Step 701" A pulse signal from the encoder 108 is input. "Step 702" The falling and rising edges of the pulse signal from the encoder 108 are detected, and by performing this edge detection, the process proceeds to step 703. "Step 703" Edges are counted and assigned to memory n. "Step 704" Store the time Δtn from the previous detected edge to the current edge. "Step 705" Write data is input in bits. "Step 706" Take the average of the past three Δt,
Furthermore, the time reduced to "1/3" is assigned to the memory T. Note that the reason for taking the average of the past three times is to reduce the influence of variations in Δt. "Step 707" Set the write level to "L". “Step 708” The data entered in step 705
It is determined whether or not the data is "1". If it is "1", the process proceeds to step 709; otherwise, the process proceeds to step 712. "Step 709" It is determined whether time T has elapsed since the edge detected this time, and when time T has elapsed, the process proceeds to step 710. "Step 710" Set the write level to "H". "Step 711" It is determined whether or not the data to be written has been completed. If it has not been completed, the process returns to step 701, and if it has been completed, the process advances to step 24 in FIG.

If it is determined in step 708 that the data is not "1", the process proceeds to step 712 as described above. “Step 712” Determine whether time (2×T) has elapsed since the edge detected this time, and
), the process advances to step 710.

From the above, the waveform shown in FIG. 5(d) is obtained.

FIG. 9 shows that in step 20, FIG.
12 is a flowchart showing the operation at the time of writing according to "Method 4" performed as in (e). "Step 801" A pulse signal from the encoder 108 is input. "Step 802" The falling and rising edges of the pulse signal from the encoder 108 are detected, and by performing this edge detection, the process proceeds to step 803. "Step 803" Edges are counted and assigned to memory n. "Step 804" Store the time Δtn from the previously detected edge to the current edge. "Step 805" Take the average of the past five Δts,
The time is assigned to memory T. Note that the reason for taking the average of the past five times is to reduce the influence of variations in Δt. "Step 806" Find the frequency f, which is the reciprocal of the time T in step 805 multiplied by 6. Of the 6 times, 2 times means that there is 2 data between the edges, and 3 times means that the data is "1/3"
It consists of controlling the rising edge. "Step 807" Two bits of write data are input. These are designated as b1 and b2. "Step 808" Set the write level to "L". "Step 809" It is determined whether the data b1 is "1" or not. If it is "1", the process proceeds to step 810; otherwise, the process proceeds to step 811. “Step 810” Wait until the time “1/f” has elapsed since the edge detection, and then proceed to step 812. "Step 811" Here, since the data b1 is not "1", the process waits for the time "2/f" to elapse from the edge detection, and then proceeds to step 812. "Step 812" Set the write level to "H". “Step 813” Wait for the elapse of “3/f” and proceed to step 814. "Step 814" Set the write level to "L". "Step 815" It is determined whether the data b2 is "1" or not. If it is "1", the process proceeds to step 816; otherwise, the process proceeds to step 817. "Step 816" Wait until the time "4/f" has elapsed since the edge detection, and proceed to step 818. "Step 817" Here, since the data b2 is not "1", the process waits for the time "5/f" to elapse from the edge detection, and then proceeds to step 818. "Step 818" Set the write level to "H". "Step 819" It is determined whether or not the data to be written has been completed. If it has not been completed, the process returns to step 801, and if it has been completed, the process advances to step 24 in FIG.

From the above, the waveform shown in FIG. 4(e) is obtained.

According to this embodiment, the amount of information recorded (written) in the magnetic storage section of each photographic frame is determined, and depending on the amount of information obtained as a result, the information shown in FIGS. 5(b) to (e) is determined. Method 1 shown in
Since information is written using one of the methods 4 to 4, appropriate magnetic recording of the film is possible even with an encoder means for detecting the amount of film movement, which does not require high resolution. In other words, the encoder means
When the number of recorded information is small compared to the number of pulses obtained in a frame (one frame), accurate recording is possible by recording in synchronization with the pulse train. Furthermore, when the amount of recorded information is large relative to the number of pulses, fairly accurate recording is possible by recording with short pseudo pulses calculated from the previous pulse interval.

[0034]

[Effects of the Invention] As explained above, according to the present invention,
Information amount detection means for detecting the amount of information to be written in each photographic frame by the magnetic head, and control for controlling the writing timing based on the output of the encoder means in accordance with the detection result of the information amount detection means. The writing timing is controlled based on the output of the encoder means for detecting the amount of film feeding in accordance with the amount of information to be written obtained by the information amount detecting means. Therefore, it is possible to write appropriate information according to each amount of information without using a highly accurate encoder means.

[Brief explanation of the drawing]

FIG. 1 is a circuit block diagram showing a schematic configuration of a camera in an embodiment of the present invention.

FIG. 2 is a diagram showing a camera according to an embodiment of the present invention from the back with the back cover removed.

FIG. 3 is a flowchart showing part of the operation of the control circuit of FIG. 2;

FIG. 4 is a flowchart showing a continuation of the operation of FIG. 3;

FIG. 5 is a time chart showing write timing according to the amount of information in an embodiment of the present invention.

FIG. 6 is a flowchart showing the operation of step 23 in FIG. 4.
It is.

FIG. 7 is a flowchart showing the operation of step 22 in FIG. 4.
It is.

FIG. 8 is a flowchart showing the operation of step 21 in FIG. 4.
It is.

FIG. 9 is a flowchart showing the operation of step 20 in FIG. 4.
It is.

[Explanation of sign]

6 Magnetic head 8 Roller 103 Control circuit 103a RAM 103b Discrimination section 108 Encoder 109 Motor control circuit 112 Head control circuit

Claims (1)

[Claims] 1. A camera using a film with a magnetic storage section, which is equipped with a magnetic head for writing information into a magnetic storage section provided on the film, and an encoder means for detecting the amount of film feeding. an information amount detection means for detecting the amount of information to be written into each photographic frame by the head; and an encoder according to the detection result of the information amount detection means.
1. A camera using a film with a magnetic storage section, characterized in that it is provided with a control means for controlling the writing timing based on the output of the data means.